import React from 'react';
import ReactDOM from 'react-dom';
import './index.css';
// class Square extends React.Component {
//   render() {
//     return (
//       <button className="square"
//         onClick={() =>this.props.onClick()}>
//         {this.props.value}
//       </button>
//     );
//   }
// }

function Square(props) {
  return <button className="square" onClick={props.onClick}>
    {props.value}
  </button>
}

class Board extends React.Component {

  renderSquare(i) {
    return <Square 
    value={this.props.squares[i]}
    onClick={()=>this.props.onClick(i)}
    />;
  }


  render() {

    return (
      <div>
        <div className="board-row">
          {this.renderSquare(0)}
          {this.renderSquare(1)}
          {this.renderSquare(2)}
        </div>
        <div className="board-row">
          {this.renderSquare(3)}
          {this.renderSquare(4)}
          {this.renderSquare(5)}
        </div>
        <div className="board-row">
          {this.renderSquare(6)}
          {this.renderSquare(7)}
          {this.renderSquare(8)}
        </div>
      </div>
    );
  }
}

class Game extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      history:[{
        squares:Array(9).fill(null),
      }],
      xIsNext:true,
      stepNumber:0,
    }
  }

  handleClick(i){
    const history = this.state.history.slice(0,this.state.stepNumber+1);
    const current = history[history.length - 1];
    const squares =current.squares.slice();
    if (calculateWinner(squares)||squares[i]) {
      return;
    }
    squares[i] = this.state.xIsNext?'X':'O'
    this.setState({
      history:history.concat([{
        squares:squares,
      }]),
      stepNumber:history.length,
      xIsNext:!this.state.xIsNext
    })
    // if (this.state.xIsNext) {
    //   squares[i] = 'X';
    // }else{
    //   squares[i] = 'O';
    // }
    // this.state.xIsNext = !this.state.xIsNext;
    // this.setState(
    //   {squares:squares}
    // )
  }

  jumpTo(step){
    this.setState({
      stepNumber:step,
      xIsNext:(step % 2) === 0,
    })

  }

  render() {
    const history = this.state.history;
    console.log(history);
    const current = history[this.state.stepNumber];
    const winner = calculateWinner(current.squares);

    const moves = history.map((step,move) =>{
      const desc = move? "Go to move #"+move : 'Go to game start';
      return (
        <li key={move}>
          <button onClick={() => this.jumpTo(move)}>
            {desc}
          </button>
        </li>
      )
    })


    let status;
    if (winner) {
      status = 'Winner: ' + winner;
    } else {
      status = 'Next player: ' + (this.state.xIsNext ? 'X' : 'O');
    }
    return (
      <div className="game">
        <div className="game-board">
          <Board 
          squares={current.squares}
          onClick={(i) => this.handleClick(i)}
          />
        </div>
        <div className="game-info">
          <div>{status}</div>
          <ol>{moves}</ol>
        </div>
      </div>
    );
  }
}

// ========================================

ReactDOM.render(
  <Game />,
  document.getElementById('root')
);

function calculateWinner(squares) {
  const lines = [
    [0, 1, 2],
    [3, 4, 5],
    [6, 7, 8],
    [0, 3, 6],
    [1, 4, 7],
    [2, 5, 8],
    [0, 4, 8],
    [2, 4, 6],
  ];
  for (let i = 0; i < lines.length; i++) {
    const [a, b, c] = lines[i];
    if (squares[a] && squares[a] === squares[b] && squares[a] === squares[c]) {
      return squares[a];
    }
  }
  return null;
}
